Titrations

Question 1

How can a soluble salt be prepared

Answer 1

By reacting an acid with a dilute solution of an alkali

Question 2

Apparatus to carry out titration

Answer 2

Burette
Conical flask
Safety pipette fillet
Pipette

Question 3

For titrations readings should be recorded to _ decimal places, ending with _ or _.

Answer 3

2
0
5

Question 4

What is a titre

Answer 4

Volume of one reactant needed to react completely with the other reactant in a titration

Question 5

Purpose of required practice how to titrate an acid and an alkali

Answer 5

Determine the reacting volumes of solutions of a strong acid and a strong alkali by titrations

Question 6

Reagents when titrating a acid and alkali

Answer 6

Acid( hydrochloric, nitric, sulphuric)
Sodium hydroxide
Suitable indicator(methyl orange)

Question 7

Hazard: dilute sodium hydroxide solution.
What is the possible harm and what precaution do we take to stop that happening

Answer 7

Causes skin and serious eye irritation

Wear gloves and eye protection and use pipette filler

Question 8

Hazard: spilling hydrochloric acid while filling the burette

What is the possible harm and how xan we prevent it

Answer 8

Causes eye irritation

Fill burette slowly below eye level, using a funnel, and wear goggles

Question 9

Step one When titrating an acid and an alkali

Answer 9

Use the pipette and pipette filler to add 25cm^3 of alkali to a clean conical flask

Question 10

Step two when titrating an acid and an alkali

Answer 10

2. Add a few drops of indicator and put conical flask on white tile

Question 11

Step 3 when titrating an acid and an alkali

Answer 11

Fill burrete with acid and note starting volume

Question 12

Step 4 when titrating an acid and an alkali

Answer 12

Slowly add the acid from burette to the alkali in the conical flask swirling to mix

Question 13

Step 5 when titrating an acid and an alkali

Answer 13

Stop adding the acid when the end point( point when the indicator first permanently changes colour) is reached. Note final volume reading

Question 14

Step 6 when titrating an acid and an alkali

Answer 14

Repeat steps 1 to 5 until you gey concordant ( titres within 0.10 cm^3 of each other) titres

Question 15

Analysis after experiment

Answer 15

At least two concordant titres should be ticked

Calculate mean titres

Question 17

What can the results of a titration be used to calculate

Answer 17

Concentration of solution

Volume of solution needed

Question 18

Calculating a concentration with moles

Answer 18

1. Calculate amount of sodium hydroxide in moles
2. Find amount of acid in moles
3. Calculate concentration of acid in moles/dm^3
4. Calculate the concentration of acid in g/dm^3

Question 19

Acids produce _______ and have a pH less than _

Answer 19

Hydrogen ions
7

Question 20

Alkalis produce _______ and have a pH higher than _

Answer 20

Hydroxide ions
7

Question 21

What is a neutral solution

Answer 21

Solution with pH 7

Question 22

Which indicator does the acidic and neutral substances stay Red and alkaline substances turn blue

Answer 22

Red litmus paper

Question 23

Which indicator does acidic solutions turn turn red, and alkaline and neutral substances stay blue

Answer 23

Blue litmus paper

Question 24

Why are all alkalis bases

Answer 24

Alkalis dissolve in water

Question 25

What is neutralisation

Answer 25

Reaction between the base and acid

Question 26

Acid + metal =

Answer 26

Salt + hydrogen

Question 27

Why are reactions between metals and acids called redox reactions

Answer 27

Because oxidation and reduction happen at the same time

Question 28

Acid + metal oxide =

Answer 28

Salt + water

Question 29

Acid + alkali =

Answer 29

Salt + water

Question 30

Acid + carbonate =

Answer 30

Salt + water + carbon dioxide

Question 32

Charge of a salt

Answer 32

0

Question 33

Making a salt required practical

Answer 33

Mix in insoluble reactant to acid until in excess Filter amd collect the filtrate Heat in water bath till small crystals appear Leave at room temp for couple of days so Bigger crystals can form

Question 34

Apparatus for making salts practical

Answer 34

Beaker Stirring rod Conical flask Filter paper and funnel Water bath Watch glass

Question 35

The solid used in the making salts required practical must

Answer 35

Include the correct metal ions React with the acid be insoluble in water

Question 36

Hazard in the making salts experiment is the hydrochloric acid. What is the risk and how can you stop it

Answer 36

Damages skin and clothes Use dilute hydrochloric acid and wear gloves

Question 37

Hazard for making salts experiment= bunsen burner and hit apparatus What is risk and how to stop it

Answer 37

Burns - don't touch the apparatus Hair or clothing catching fire - tie back hair and keep clothes tucked in

Question 38

Whe does a solution form

Answer 38

When a solute dissolves in a solvent

Question 39

What is a dilute vs concentrated solution

Answer 39

Solution which contains a relatively small vs relatively large amount of dissolved solvent

Question 40

What are strong acids

Answer 40

Acids which completely disassociate into ions in a solution

Question 41

What are weak acids

Answer 41

Acids which only partially dissociate in a solution Eg ethanol

Question 42

What is pH of a solution measured by

Answer 42

Concentration of hydrogen ions